Graphene Oxide Covalently Functionalized with 5-Methyl-1,3,4-thiadiazol-2-amine for pH-Sensitive Ga³⁺ Recovery in...

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Graphene oxide (GO) is a versatile nanomaterial with potential applications in adsorption.
• Developing selective adsorbents for metal ions is crucial for environmental remediation and resource recovery.
• 5-methyl-1,3,4-thiadiazol-2-amine (MTA) functionalization offers a route to tailor GO properties.

Purpose of the Study:

• To develop a novel graphene-based composite for selective Gallium(III) ion (Ga³⁺) adsorption.
• To investigate the adsorption capacity, kinetics, and mechanism of the composite for Ga³⁺.
• To evaluate the potential of the composite for Ga³⁺ separation from aqueous solutions.

Main Methods:

• Covalent functionalization of graphene oxide with 5-methyl-1,3,4-thiadiazol-2-amine (MTA) to create GO-MTA.
• Batch adsorption experiments to study the effect of contact time, temperature, initial concentration, and pH.
• Adsorption isotherm and kinetic modeling using Langmuir and pseudo-second-order models.
• Characterization using SEM-EDS, elemental mapping, FT-IR, and XPS to elucidate the adsorption mechanism.

Main Results:

• The GO-MTA composite exhibited selective sorption of Ga³⁺ (48.20 mg g^-1) over In³⁺ and Sc³⁺.
• Optimized conditions yielded a maximum adsorption capacity of 55.6 mg g^-1 for Ga³⁺.
• Adsorption followed pseudo-second-order kinetics and Langmuir isotherm models, indicating chemisorption and monolayer adsorption.
• Characterization confirmed the adsorption mechanism involving functional groups on GO-MTA.

Conclusions:

• The GO-MTA composite is a promising adsorbent for selective Ga³⁺ removal.
• The material demonstrates high adsorption capacity and efficiency for Ga³⁺ enrichment.
• This study highlights the potential of functionalized graphene oxide for separating valuable or toxic metal ions from aqueous environments.